There has always been, and will always be, pressure for improvements to the bearings of turbine meter rotors. One, there is the overhanging need for a bearing which will provide for flow reversals. Lubrication will never be completely satisfactory. Now the sanitary market requires more simplicity to reduce retention of food in which harmful bacteria will develop. All configurations of turbine meter structure are being redesigned to get the simple form which will not harbor collections of food-fluids metered or which can be readily flushed clean of this residue.
The food industry is active in establishing standards for meter structures which must be brought into direct contact with food. No turbine meter design has been given an universal stamp of approval. This art has the problem of providing the meter function with structure which is simple enough to meet the evolving sanitary standards of industry as they apply to measurement.
The turbine meter disclosed in U.S. Patent Harris et al., U.S. Pat. No. 4,000,932 has been satisfactory in the range of small flow line sizes, i.e. 3/4 to 2". However, there are some indications that the structure becomes unstable in the sizes above 2 inches. Additional support must be provided for the rotor to stabilize the structure. The ceramic bearing surfaces, as provided in the disclosure U.S. Pat. No. 4,000,932, remains a high-water mark of this feature of meter development which must be combined with the additional rotor support.